Method and device for operating electric arc furnaces and/or resistance furnaces

Abstract

The aim of the invention is to provide a means of also cooling the lower part of electric arc furnaces and/or resistance furnaces. To this end, said lower part—the actual melting vessel ( 4 )—is surrounded with a jacket ( 9 ) at a certain distance, forming a shell, and the resulting intermediate space is configured as a cooling device ( 10 ) and subjected to the action of a cooling medium ( 14 ).

What is claimed is:  
     
       1. A resistance melting furnace, comprising: 
       a melting vessel having a refractory lining and an outer furnace wall, the melting vessel having a furnace bottom and lower lateral walls;  
       an upper part cooled by a first cooling medium and comprising a lid and upper lateral walls;  
       a shell-shaped cooling device enclosing the outer furnace wall, wherein a second cooling medium flows through the cooling device and is in direct contact with the outer furnace wall, wherein the second cooling medium is transported in the cooling device by convection,  
       a conveying device arranged externally on the cooling device and configured to convey the second cooling medium in addition to the convection of the second cooling medium.  
     
     
       2. The resistance melting furnace according to  claim 1 , wherein the cooling device has a mantle having a contour corresponding to a contour of the outer furnace wall, wherein the mantle is arranged on the melting vessel, wherein the cooling device has at least one inlet opening and at least one outlet opening for the second cooling medium. 
     
     
       3. The resistance melting furnace according to  claim 2 , wherein the inlet opening is arranged centrally at the furnace bottom and the outlet opening is arranged laterally at an upper end of the lower lateral walls. 
     
     
       4. The resistance melting furnace according to  claim 1 , further comprising a conveying device arranged externally on the cooling device and configured to convey the second cooling medium. 
     
     
       5. The resistance melting furnace according to  claim 1 , wherein the second cooling medium flows in a closed circuit through the cooling device. 
     
     
       6. A resistance melting furnace, comprising: 
       a melting vessel having a refractory lining and an outer furnace wall, the melting vessel having a furnace bottom and lower lateral walls;  
       an upper part cooled by a first cooling medium and comprising a lid and upper lateral walls;  
       a shell-shaped cooling device enclosing the outer furnace wall, wherein a second cooling medium flows through the cooling device and is in direct contact with the outer furnace wall, wherein the cooling device has cooling ribs arranged on the outer furnace wall.  
     
     
       7. A resistance melting furnace, comprising: 
       a melting vessel having a refractory lining and an outer furnace wall, the melting vessel having a furnace bottom and lower lateral walls;  
       an upper part cooled by a first cooling medium and comprising a lid and upper lateral walls;  
       a shell-shaped cooling device enclosing the outer furnace wall, wherein a second cooling medium flows through the cooling device and is in direct contact with the outer furnace wall, further comprising:  
       a heat recovery device, wherein the cooling device comprises an outlet line and an inlet line, wherein the heat recovery and the cooling device are connected to one another via the inlet line and the outlet line and form a closed circuit; and  
       at least one conveying device arranged in at least one of the inlet line and the outlet line.  
     
     
       8. The resistance melting furnace according to  claim 7 , wherein the at least one conveying device is a blower or a pump. 
     
     
       9. The melting furnace according to  claim 7 , further comprising a measuring and control device having control lines and a measured data line, wherein at least one of the heat recovery device and the conveying device are connected by the control lines to the measuring and control device, wherein the measuring and control device is adapted to receive measured values of an operating temperature of the electric arc melting furnace or resistance melting furnace via the measured data line. 
     
     
       10. The resistance melting furnace according to  claim 2 , wherein the outlet opening is connected to a chimney for air convection cooling.